KR101558363B1 - Method and system for controlling charging and discharging of battery - Google Patents

Abstract

The present invention relates to a method and system for controlling charging and discharging of a battery of a hybrid vehicle. The method includes: detecting a temperature of a battery; Confirming a battery state of charge (SOC), a first maximum discharge output value, and a first maximum charge output value corresponding to the temperature of the battery; Selecting a lowest SOC among SOCs that can use the maximum discharge output value that is the same as the first maximum discharge output value; Changing the first maximum charge output value to a second maximum charge output value corresponding to the selected lowest SOC; And performing charging and discharging of the battery using the changed second maximum charging output value at the detected temperature.

Description

TECHNICAL FIELD [0001] The present invention relates to a method and system for controlling charge and discharge of a battery,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging / discharging control method and system for a battery, and more particularly, to a charging / discharging control method and system for controlling a charging / And more particularly, to a charging / discharging control method and system for a battery.

As is known, a hybrid electric vehicle uses an internal combustion engine and a battery power together. That is, the hybrid vehicle efficiently combines the power of the internal combustion engine and the power of the drive motor.

1, the hybrid vehicle includes, for example, an engine 10; A drive motor 20; An engine clutch (30) for interrupting power between the engine (10) and the drive motor (20); A transmission 40; A differential gear device 50; A battery 60; A starter generator (70) for starting the engine (10) or generating power by the rotational force of the engine (10); And a wheel 80. As shown in Fig.

Although the starter generator 70 serves both as a starter motor or a generator, since the present specification relates to engine starter, the starter generator 70 is referred to herein as a starter motor.

The hybrid vehicle further includes: a hybrid control unit (HCU) 200 for controlling the overall operation of the hybrid vehicle; An engine control unit (ECU) 110 for controlling the operation of the engine 10; A motor control unit (MCU) 120 for controlling the operation of the driving motor 20; A transmission control unit (TCU) 140 for controlling the operation of the transmission 40; And a battery control unit (BCU) 160 for controlling and managing the battery 60. [

The battery controller 160 may be referred to as a battery management system (BMS). The starter generator 70 may also be referred to as an integrated starter & generator (ISG) or a hybrid starter & generator (HSG).

The hybrid vehicle includes an EV mode (electric vehicle mode), which is a pure electric vehicle mode using only the power of the driving motor 20; An HEV mode (hybrid electric vehicle mode) in which the rotational force of the engine 10 is used as a main power and the rotational force of the drive motor 20 is used as an auxiliary power; A regenerative braking mode (RB mode) for recovering braking and inertia energy during braking or inertia of the vehicle through power generation of the drive motor 20 and charging the battery 60; And the like.

The hybrid vehicle has to appropriately control and / or manage the charge / discharge of the battery. As one example of the prior art for this purpose, Patent Application No. 10-2010-0122233 entitled " Battery Management Device and Method of Hybrid Vehicle " have.

One embodiment of the prior art provides an arrangement for variably expanding a reference region for performing charging and discharging of a battery in an automatic constant-speed cruise, thereby providing fuel economy improvement.

As another embodiment of the prior art, Patent Application No. 10-2011- 86389 (entitled " Method for Managing Hybrid Vehicle Batteries ").

Another embodiment of the above prior art provides a method of managing the remaining amount of a battery for a hybrid vehicle according to a road gradient and a method of setting charging ranges for determining charge and discharge differently at the time of running on a flat plate, do.

Although the above-described embodiments of the prior art achieve the intended purpose, they have the following disadvantages.

1. It is nothing but a passive control that limits the number of times the battery is charged / discharged by varying the SOC (state of charge) range rather than improving the charge output, which affects the actual fuel economy.

2. Applicable only to the applicable method according to the running condition (automatic cruise control) or the gradient condition of the road (flat, back plate, steel plate).

3. A device for determining a separate road gradient (slope) is required to grasp the state of the running state and / or the gradient state of the road.

4. Complex logic is required to make use of data from all controllers.

5. The actual hybrid vehicle's running state is very unstable because most of the SOCs move within the normal range and travel to the high or low range is extremely limited.

The matters described in the background section are intended to enhance the understanding of the background of the invention and may include matters not previously known to those skilled in the art.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a battery charge / discharge control method and system capable of achieving a charge output and a fuel consumption improvement of a battery by controlling charge / discharge of the battery by adjusting a charge output value affecting fuel consumption in a hybrid vehicle .

According to an aspect of the present invention, there is provided a method of controlling charge / discharge of a battery of a hybrid vehicle, the method comprising: detecting a temperature of the battery; Determining a first maximum discharge output value and a first maximum charge output value corresponding to a temperature of the battery and a battery state of charge (SOC); Selecting a lowest SOC among SOCs that can use the maximum discharge output value that is the same as the first maximum discharge output value; Changing the first maximum charge output value to a second maximum charge output value corresponding to the selected lowest SOC; And performing charging and discharging of the battery using the changed second maximum charging output value at the detected temperature.

The maximum discharge output value and the maximum charge output value corresponding to the temperature and the SOC of the battery can be confirmed in a battery discharge output map and a battery charge output map built in a battery management system (BMS).

The changeable second maximum charge output value may be larger than the first maximum charge output value.

The SOC corresponding to the first maximum charge output value may be larger than the SOC corresponding to the second maximum charge output value.

According to another aspect of the present invention, there is provided a charge / discharge control system for a battery of a hybrid vehicle, comprising: a battery management system (BMS) for managing and controlling a battery; A temperature sensor for detecting a temperature of the battery; And a controller for controlling charging and discharging of the battery on the basis of the battery temperature detected by the temperature sensor and the information embedded in the BMS, wherein the controller controls the charging and discharging of the battery of the hybrid vehicle according to the embodiment of the present invention. And can be operated by a set program for performing charge / discharge control method.

The battery management system (BMS) may include a discharge output map and a charge output map for charge / discharge control.

The controller may use the data in the discharge output map and the charge output map for charge / discharge control.

As described above, according to the embodiment of the present invention, the charge output of the battery and the fuel efficiency improvement can be achieved by controlling the charge / discharge of the battery by adjusting the charge output value that affects the fuel efficiency in the hybrid vehicle.

According to the embodiment of the present invention, not only the passive control according to the SOC region, which is related to the number of charging and discharging, but also the charging output and the fuel efficiency improvement of the battery can be achieved through the positive control of increasing the charging output of the actual battery.

According to the embodiment of the present invention, the charging output and the fuel economy improvement of the battery can be achieved irrespective of the road gradient state, the running state, and the engine on / off state.

1 is a conceptual block diagram of a general hybrid vehicle.
2 is a block diagram of a charge / discharge control system for a battery of a hybrid vehicle according to an embodiment of the present invention.
3 is a flowchart of a charge / discharge control method of a battery of a hybrid vehicle according to an embodiment of the present invention.
4 is an exemplary table of a discharge output map applied to an embodiment of the present invention.
5 is an exemplary table of a charge output map applied to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms.

Throughout the specification, when a section includes a constituent element, it is understood that it can include other constituent elements, not excluding other constituent elements unless specifically stated otherwise. In addition, parts denoted by the same reference numerals throughout the specification denote the same components.

2 is a block diagram schematically showing a charge / discharge control system for a battery of a hybrid vehicle according to an embodiment of the present invention.

The charge / discharge control system of the battery of the hybrid vehicle according to the embodiment of the present invention is a control system that changes the output value extraction logic according to the battery SOC to raise the charge output.

The charge / discharge control system for the battery of the hybrid vehicle according to the embodiment of the present invention includes a battery management system (BMS) 160 for managing and controlling the battery 60; A temperature sensor 65 for detecting the temperature of the battery 60; And a controller 300 for controlling the charging and discharging of the battery 60 based on the battery temperature detected by the temperature sensor 65 and information embedded in the BMS 160. [

The battery 60, the temperature sensor 65 and the BMS 160 may correspond to those used in the prior art. Therefore, a detailed description thereof will be omitted.

The BMS 160 may include a discharge output map 162 and a charge output map 164 as shown in FIGS. 4 and 5 for charging / discharging control.

The controller 300 may include one or more microprocessors and / or microprocessors that operate according to a set program, and the set program may be executed by the controller 300 to perform a charge / discharge control method of a hybrid vehicle according to an embodiment of the present invention As shown in FIG.

The controller 300 may include a BMS or be included in a BMS.

The controller 300 may utilize the data in the discharge output map 162 and the charge output map 164 for charge / discharge control.

Hereinafter, a charging / discharging control method for a battery of a hybrid vehicle according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 is a flowchart illustrating a charge / discharge control method of a battery of a hybrid vehicle according to an embodiment of the present invention.

As shown in FIG. 3, the controller 300 receives the temperature of the battery 60 detected through the temperature sensor 60 (S100).

When the battery temperature detected by the temperature sensor 60 is inputted, the controller 300 refers to the discharge output map 162 and the charge output map 164 built in the BMS 160, The first maximum discharge output value and the first maximum charge output value corresponding to the temperature and the battery state of charge (SOC) are checked (S200).

It is well known that the discharge and charge output values of the battery 160 in the hybrid vehicle are typically determined using the discharge and charge output maps (see FIGS. 3 and 4) embedded in the BMS 160.

When the step S200 is performed, the controller 300 selects the lowest SOC among the SOCs that can use the maximum discharge output value equal to the identified first maximum discharge output value (S300) And changes to the second maximum charge output value corresponding to the SOC (S400).

If the first maximum charge output value has been changed to the second maximum charge output value corresponding to the selected lowest SOC, the controller 300 determines whether the battery is fully charged or not, using the changed second maximum charge output value at the detected temperature in step S100. (S500).

For example, in the case of a general hybrid vehicle, the maximum charge output value is normally 44.5 kW, the discharge output value is 47 kW, and these output values are adjusted to values less than or equal to the maximum value depending on the temperature and SOC.

In FIGS. 4 and 5, when the temperature of the battery is 30 ° C. and the SOC is 55, the charging output value is 39.7 kW and the discharge output value is 47 kW.

The embodiment of the present invention is characterized in that the SOC is applied down to the SOC permitting the maximum discharge output when the SOC region can use a value equal to or greater than the maximum discharge output.

In FIG. 4, the discharge output map 162 means that the output value can be used in a region above the SOC at the use temperature (battery temperature) at that time.

For example, an SOC region capable of using a maximum discharge value of 47 kW at 25 캜 is 55 or more, and SOC 40 or more at 35 캜.

That is, if the actual SOC at 25 ° C is 55 or more, it is recognized as 55, and if the actual SOC at 35 ° C is 40, it is recognized as 40.

More specifically, in the case of SOC 60 at 25 캜, the discharge output value is 47 kW and the charge output value is 33.95 kW. At this time, the controller 300 recognizes the actual SOC 60 as the minimum SOC of 55, which is the minimum SOC allowing the maximum discharge output value of 47, and sets the discharge output value to 47 kW and the charge output value to 35.28 kW.

4 and 5, when the battery temperature is 30 ° C. and the SOC is 55, when the controller 300 determines that the SOC is 45, the controller 300 determines that the discharge output value is equal to or less than 47 kW The output value can be increased from 39.7 kW to 42.56 kW.

The embodiment of the present invention is attributed to the charge / discharge output characteristics of the battery. That is, if the temperature is equal to or higher than a certain SOC at a given temperature, the discharge output is always possible to be greater than or equal to the predetermined value.

That is, referring to FIG. 4 and / or FIG. 5, if the discharge output value is 40 kW in the SOC 55, if the discharge output value is always 40 or more in the case of SOC 55 or more and the charging output value is 30 kW in SOC 55, At least 30kW is always possible.

Therefore, in the high SOC region where the discharge output value is sufficient but the charge output value is insufficient, the discharge output value can be used as it is, and the charge output value can be improved.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It belongs to the scope of right.

60: Battery
65: Temperature sensor
160: Battery Management System (BMS)
162: Discharge output map
164: charge output map
300: controller

Claims (7)

As a method for controlling charging and discharging of a battery of a hybrid vehicle,
Detecting a temperature of the battery;
Determining a first maximum discharge output value and a first maximum charge output value corresponding to a temperature of the battery and a battery state of charge (SOC);
Selecting a lowest SOC among SOCs that can use the maximum discharge output value that is the same as the first maximum discharge output value;
Changing the first maximum charge output value to a second maximum charge output value corresponding to the selected lowest SOC; And
Performing charge / discharge of the battery using the changed second maximum charge output value at the detected temperature;
And controlling the charging / discharging of the battery of the hybrid vehicle.
The method of claim 1,
Wherein the maximum discharge output value and the maximum charge output value corresponding to the temperature and the SOC of the battery are confirmed in a battery discharge output map and a battery charge output map built in a battery management system (BMS) A method for controlling charge / discharge of a battery.
The method of claim 1,
Wherein the second maximum charge output value is larger than the first maximum charge output value.
The method of claim 1,
Wherein the SOC corresponding to the first maximum charge output value is greater than the SOC corresponding to the second maximum charge output value.
As a system for controlling charging and discharging of a battery of a hybrid vehicle,
A battery management system (BMS) for managing and controlling the battery;
A temperature sensor for detecting a temperature of the battery;
And a controller for controlling charging and discharging of the battery based on the battery temperature detected by the temperature sensor and information embedded in the BMS,
Wherein the controller is operated by a set program for performing the method according to any one of claims 1 to 4. A system for controlling charging and discharging of a battery of a hybrid vehicle,
The method of claim 5,
Wherein the battery management system (BMS) includes a discharge output map and a charge output map for charge / discharge control.
The method of claim 6,
Wherein the controller uses data in the discharge output map and the charge output map for charge / discharge control.

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